Ivory Coast's president declared three days of national mourning and promised a speedy investigation into the New Year's Day stampede that killed 60 people, most of them women and children.

"The president of the republic offers his saddest condolences to the families and close relations of the victims and ensures them of his compassion in those painful circumstances," President Alassane Ouattara's office said in a statement issued Tuesday night.

Ouattara went to the scene of the disaster and has ordered the government to take care of the injured, his office said.

"He also asked an investigation to be carried out as soon as possible to determine the circumstances and causes of this stampede," the statement said.

The horror unfolded about 1 a.m. after a New Year's Eve fireworks show in Abidjan, the West African country's largest city and former capital. The dead included 26 children, 28 women and six men, Youth Minister Alain Lobognon reported via Twitter.

JUST WATCHED

Ivory Coast stampede cause unclear

MUST WATCH

Ivory Coast stampede cause unclear02:06

PLAY VIDEO

Many of the victims were trampled on or suffocated by the surging crowd, a senior fire official said on national television. Rescue workers were at the scene two hours later but could not save the victims, the official AIP news agency said. AIP had reported earlier that all the victims were all children, ranging in age from eight to 15.

A police official in Abidjan told CNN that most of the victims were young people who wanted to join in the celebration while their elders stayed at home. The stampede occurred in an area of narrow streets, according to the official, who did not want to be named as he is not authorized to talk to the media.

He said the parents of those involved were at the hospitals and were being assisted by state authorities.

Before the night's events took a deadly turn, AIP reported that thousands of people had poured into the streets to join the celebration, seen by some as symbolizing the nation's return to peace.

Nearly 5,000 extra personnel were deployed to ensure people's security, the news agency said, most of them in the Plateau area.

Ivory Coast suffered months of violence following disputed presidential elections in November 2010. Laurent Gbagbo, then the incumbent president, refused to step down after Ouattara was declared the winner.

Gbagbo was arrested five months later and is now awaiting trial at The Hague, in the Netherlands, accused of crimes against humanity for the civil unrest and deaths. The International Criminal Court also wants Ivory Coast to hand over his wife, Simone Gbagbo, to face allegations of crimes against humanity.

The West African nation is home to around 22 million people, according to the CIA World Factbook.